Refrigeration



March 26, 1940. c, H GALOFF 2,195,288

REFRIGERATION Filed Dec. 21, 1938 2 Sheets-Sheet 1 I g/ INVENTOR. BY M7 oaza'm ATTORNEY.

March 26, 1940. c, SHAGALQFF 2,195,288

REFRIGERATION Filed Dec. 21, 1938 2 Sheets-Sheet 2 BY INVENTOR.

ATTORNEY.

Patented Mar. 26, 1940 UNITED STATES PATENT OFFICE REFRIGERATION Delaware Application December 21, 1938, Serial No. 246,952

5 Claims.

My invention relates to refrigeration and more particularly to quick melting of frost on the cooling element of an absorption type refrigeration system.

I maintain a segregated quantity of absorption liquid in an absorption type refrigeration system, and heat this liquid to expel refrigerant vapor and conduct the vapor into the cooling element of the system when it is desired to quick- 1y raise the temperature thereof to melt frost, as

more fully set forth in the following description in connection with the accompanying drawings of which Fig. 1 shows more or less dlagrammatically a pressure equalized absorption refrigera- 15 tion system embodying the invention; and Fig. 2 is a similar view ofa system like that in Fig. 1 illustrating a modification of the invention.

Referring to Fig. 1, a generator I includes a horizontal portion having a chamber I I and a chamber I2, a standpipe I3 connected at its lower end to chamber I I, and a thermo-syphon or vapor liquid lift conduit I4 extending from within chamber I2 upward to the upper part of standpipe I3. The generator is heated by a gas burner 25 I5 arranged so that the flame projects into the.

lower end of a flue I6 which extends through chambers II and I2. The upper end of standpipe I3 is connected by a conduit II to the upper end of an air cooled condenser I8. A coil type 0 evaporator I9 is located in a refrigerator storage compartment 20. The upper end of evaporator I9 is connected to the lower end of condenser I8 by a conduit 2|. The upper end of evaporator I9 is also connected by a conduit 22, inner passage of a gas heat exchanger 23, and a conduit 24 to an absorber vessel 25. The upper part of vessel 25 is connected to the lower end of an air cooled absorber coil 26. The upper end of absorber coil 26 is connected by a conduit 21, 4o outer passage of gas heat exchanger 23, and a conduit 29 to the lower end of evaporator coil I9.

The lower part of absorber vessel 25 is connected by a conduct 29, outer passage of a liquid heat exchanger 30, and a conduit 3| to generator chamber I2. Generator chamber II is connected by a conduit 32, inner passage of liquid heat exchanger 30, and a conduit 33 to the upper part of absorber coil 26.

At a level adjacent the level of the upper end 50 of absorber coil 26 I provide an auxiliary vessel 34 having a flue 35. Vessel 34 is heated by a gas burner 36 arranged so that the flame is projected upward in the lower end of flue 35. The top of vessel 34 is connected by an upward looped 55 conduit 31 to the evaporator I9. The bottom of vessel 34 is connected by a downward looped conduit 38 to the lower part of standpipe I3.

Gas flows to burner 36 through a conduit 39. Gas flows to main burner I5 through a conduit 40. In conduit 40 is a thermostatic gas valve 4I connected by a capillary tube 42 to a sensitive element 43 on the evaporator I9 so that valve 4| operates responsive to a temperature condition affected by the evaporator. A gas supply conduit 44 is connected by a selective valve 45 to gas conduits 39 and 40. Small conduits 46 and 41 provide bypass flow of gas around valve 45 to conduits 39 and 40 respectively to maintain pilot flames in burners 36 and I5 when one or the other is cut off by valve 45.

:In operation, valve 45 is normally turned to the position shown and burners I5 and 36 lighted, burner 36 operating with a pilot flame and burner I5 operating with a flame determined by thermostatic valve 4I. Heating of generator III by burner I5 causes expulsion of refrigerant vapor, such as ammonia, from solution in absorption liquid, such as water. Vapor formed in chamber I2 rises through conduit I4 and causes upward flow of liquid from chamber I2 into standpipe I3 in known manner. Vapor expelled in chamber II rises through standpipe I3. Vapor flows from the upper end of standpipe I3 through conduit I! to the upper end of condenser l8. Vapor is condensed to liquid in condenser I8. The liquid flows from the lower end of the condenser through conduit 2I into evaporator I9.

Refrigerant liquid flows downward in evaporator I9 and evaporates and difiuses into an inert auxiliary pressure equalizing gas, such as hydrogen, producing a refrigerating effect for cooling compartment 20. Gas and vapor mixture flows from the upper end of evaporator I9 through conduit 22, gas heat exchanger 23, and

conduit 24 into absorber vessel 25. The vapor thence flows into absorber 26.

Weakened absorption liquid flows from generator chamber II through conduit 32, liquid heat exchanger 30 and conduit 33 into the upper end of absorber 26. Absorption liquid runs downward through the absorber coil into vessel 25. Refrigerant vapor is absorbed into solution in the absorber. Weak gas flows from the upper end of absorber coil 26 through conduit 21, gas heat exchanger 23, and conduit 28 back to the 5c evaporator. Enriched absorption ,liquid flows from absorber vessel 25 through conduit 29, liquid heat exchanger 30, and conduit 3I into generator chamber I 2.

When the system is operated so that evaporator I9 is maintained at a temperature below freezing, this part becomes coated with frost which should be removed at intervals. To do this, valve 45 is turned so that gas supply conduit 44 is connected to conduit 36. This puts burner 36 on full flame and reduces burner l5 to pilot flame. The burner 36 heats vessel '34. This vessel contains absorption liquid at substantially the same surface level as that in the generator standpipe IS. The heat of burner 36 causes ammonia vapor to be expelled from solution in vessel 34. The vapor flows from vessel 34 through conduit 31 into the evaporator I9. This causes the temperature of evaporator Hi to rise quickly and cause melting of frost on the outer surface. When the coating of frost is removed, valve 45 is returned to the position shown in the drawings and normal operation as described above is resumed.

The refrigeration system shown in Fig. 2 is identical with that described in connection with Fig. 1, and like parts areindicated by the same reference numerals. A generator flue I6 is provided with a bypass section 49 controlled by a damper50. Vessel 34 shown in Fig. 1 is omitted and conduits 3'i'and 38 .in Fig. 1 combine into a single conduit 5| which extends upward through the flue branch 49. The two-way valve of Fig. 1 is replaced by an ordinary shutoff valve 52.

Flue damper 50 is normally closed as shown in Fig. 2 and conduit 5| is not heated. When it is desired to melt frost on the evaporator I9, gas valve 52 is closed'to reduce burner [5 to pilot flame, and damper 50 is opened, causing products of combustion to flow through the flue branch 49. Solution in conduit 5| is heated and refrigerant vapor is expelledfrom solution. The hot vapor flows upward through conduit 5| into evaporator l9 and the evaporator-absorber gas circuit. When the frost is melted, damper 50 is closed and gas valve 52 opened, returning the refrigeration system to normal operation under the control of thermostatic valve ll as described in connection with Fig. 1.

Various other modifications and changes may be made within the scope of the invention which is not limited except as indicated in the following claims.

What is claimed is: I

1. An absorption refrigeration system having a place of evaporation, a place of absorption, a place of condensation, and a plurality of places of vapor expulsion connected to receive liquid from said place of absorption, means including said place of condensation for conducting refrigerant fluid from one of said places.of expulsion to said place of evaporation, means for conducting vapor directly from another of said places of expulsion to said place of evaporation, and means for heating said places of vapor expulsion in alternation.

2. A method of refrigeration which includes evaporating liquid refrigerant fluid at a low vapor pressure to produce refrigeration, creating said low vapor pressure by absorption of refrigerant fluid vapor into an absorbent, expelling refrigerant fluid vapor from-said absorbent at a first place of vapor expulsion, condensing expelled vapor to liquid, supplying the liquid for said evaporation step, and intermittently raising said low vapor pressure by introducing expelled vapor from a second place of vapor expulsion directly into the presence of liquid refrigerant fluid to be evaporated.

3. In an absorption refrigeration system including an evaporator, an absorber, a generator, and a condenser, a second generator, said first generator and absorber being connected to form a circuit for absorption liquid, and said second generator being connected to contain absorption liquid in said circuit and deliver vapor to said evaporator, and means to heat said second generator to cause flow of vapor to said evaporator to raise the temperature of the evaporator when it is desired to cause melting of frost thereon.

4. In a refrigeration system as set forth in claim 3, a heater for said first generator, and means for turning said heater off when said means to heat said second generator is started.

5. A refrigeration system as set forth in claim 3 in which said first generator is heated by a burner, and a flue for conducting heat and products of combustion of said burner, and said means to heat said second generator is a controlled branch of said flue.

HARRY C. SHAGALOFF. 

